In known methods for perforating a printed circuit board, reference patterns for identifying perforating positions formed on the printed circuit board are imaged by TV cameras. The image signals thereof are stored. Based on these image signals, central positions of the patterns are calculated by an image processing device. The central positions of the patterns are perforated after moving the printed circuit board on XY tables in XY directions in accordance with the calculated values.
When perforating a plurality of holes in a single printed circuit board, each perforationg is made in one portion of the board in the method described above. After moving the printed circuit board, the next hole is bored by the same method.
In the conventional perforating method, only one perforating device is employed. Therefore, when a plurality of positioning holes are perforated in the single printed circuit board, the same operation has to be carried out two or more times. If there is an error between the patterns indicating the perforating positions, the perforations are directly effected. This exerts an influence on an the accuracy of perforating of lands of the wiring patterns, which is to be effected in the next step.